1. Field of the Invention
The present invention pertains to computer-related image forming methods and apparatuses that print images corresponding to image files, such as page descriptions, stored on a computer readable medium. More particularly, the present invention is directed to printing methods and apparatuses that combine a data image with an image of a form, such as a business form that is stored in memory on the printer, where the data image and image of the form are encoded in industry standard printer language commands. During a print operation, the data image is aligned with the image of the form, much like how conventional blank business forms are completed with typewritten data, and printed as a composite image on an image holding medium, such as paper, overhead transparencies, and the like.
2. Discussion of the Background
The trend in modern business operations it toward automation, however most business operations still rely on standard business forms in day-to-day operations. FIG. 1 shows an example form that is commonly completed by hand. Using modern software such forms may be completed via computer assistance by displaying an image of the form on a display and entering data in specific fields of the form by way of a keyboard, mouse or other data input device. Once the computer-based form is completed, an operator prints the completed form, with the data input thereon, by downloading the form and data to a printer so as to obtain a completed hard-copy (see, e.g., FIG. 2).
In some cases, the computer-based form may be relatively complex and include lines, text, graphics, shading or the like. Conventional standard printer languages, such as PostScript or printer control language (PCL), help to resolve the complexity and inefficiencies of downloading large amounts of graphics data, on a pixel-by-pixel basis, by converting the graphics information into printer commands that are recognizable and interpreted by the printer. Accordingly, due to the large market presence of printers that are compatible with standard printer languages, the present inventors have identified that the most commercially valuable printer utilities and applications will be compatible with the standard printer languages. Custom printer packages simply do not have broad commercial appeal.
As identified by the present inventors, the form information can often be very large, even if encoded in a standard printer language, but the data information used to complete the forms is generally relatively small. Thus much of the time required to download and print the completed form is dedicated to the repeated downloading of the form information. Aside from being time inefficient, repeated printing of the form places significant communications capacity demands on the link between the computer and the printer, which is particularly troublesome when the computer is connected to the printer via a network.
Some conventional printers, such as laser printers, include a mass storage device, such as a hard disk, semiconductor memory, or other memory used for storing font information and graphics files such as logos. Retrieving and using this graphics information is handled seamlessly by the standard printer driver, such as a PostScript printer driver, employed in the computer because the content of the graphics information is predetermined and can thus be accounted for in the printer driver. However, as will be discussed and as identified by the present inventors, conventional utilities are not available for downloading large image files (such as templates of forms) to be stored in the printer, and standard printer drivers are not available for making use of the large image files with a PostScript description of the data image (to be overlaid on the form). As currently identified, a risk with combining the large image file with the data image is that the large image file will leave its markings on a frame buffer, the contents of which will be printed by the printer, and the markings will adversely affect a graphics and execution state of a PostScript interpreter. Moreover, the large image file may instill an adverse lasting effect that impacts other print operations because the large graphics files changes a graphics state and execution state of the PostScript interpreter.
U.S. Pat. No. 5,050,101 describes another printing apparatus that includes a memory which stores several types of form information in a custom format. Because the information is encoded in a custom format, the printing apparatus is not compatible with standard printing languages, and thus could not use a standard PostScript printer driver, for example. In this apparatus, respective data sets are cataloged with certain, application unique, "delimiter codes" that are used to arrange information stored in the printer memory, and later used to construct a composite image. The unique codes are then used to arrange the respective data sets into composite images which are then printed, by way of a custom interpreter.
As recognized by the present inventors, the above described printing apparatus relies on unique commands that are not compatible with other standard printer languages, such as PostScript, and thus, could not be conveniently used with various applications operating under commonly used operating systems such as WINDOWS 95 or WINDOWS 3.1, for example.
U.S. Pat. No. 4,944,614 describes a form overlaying type printing apparatus in which image data (which may be representative of a form) is downloaded to a printer at the same time as other data. The printer includes an input control section that distinguishes the image data from the other data and separately stores the respective data in different memories. Subsequently, only variable data are input to the printer from the computer, and the printer constructs respective composite images by retreiving selected portions of stored image and other data according to the variable data.
As recognized by the present inventors, conventional devices do not encode the image file and form data in a standard printer description design language such as PostScript so that the forms may be employed by all standard application software and printers that support the PostScript printer language. For a general description regarding PostScript language, see, e.g. Adobe Systems Incorporated, "PostScript Language Reference Manual", Addison-Wesley Publishing Company, Inc., Second Edition, 1990, and McGilton, et al, "PostScript by Example", Addison-Wesley Publishing Company, Inc., 1992, the entire contents of both of which are incorporated herein by reference.
Aside from print "overlaying" applications that use unique approaches to encoding data, several variants of standard printer description languages are available for encoding images, but the present inventors have determined that most standard printer description languages do not support mass storage device access as a standard feature. PCL is an example of a standard printing language that does not meet this criteria. In contrast to PostScript, which is a recognized exception, the other standard printer description languages fail to take advantage of the synergism between standard, and thus broadly applicable, printer design languages, and the use of file management features that enable the operator to organize and maintain form files on the printer's mass storage devices such as a hard disk, optical disk, or semiconductor memory bank, for example.